Back during The Great Depression, President Herbert Hoover ordered the deportation of ALL illegal aliens in order to make jobs available to American citizens that desperately needed work..
Harry Truman deported over two million illegal after WWII to create jobs for returning veterans.
And then again in 1954, President Dwight Eisenhower deported 13 million Mexican Nationals! The program was called 'Operation Wetback'. It was done so WWII and Korean Veterans would have a better chance at jobs.
It took 2 Years, but they deported them!
Now....if they could deport the illegal's back then - they could sure do it today.
Please note. The key word here is "illegal."